I saw that there were many different kinds of fishes. before i said that it could have been that they evolved in the pond or that they were put in there from another location. I think that it could also be that the fishes changed due to their environment. Maybe its the algae, the water (type of water, murky-shallow-etc.), or the other species that are around them.
another observation i made was that the small fishes swim around in groups, but they also swim around bigger fishes. Before i thought that they only swam together to avoid confrontation with the big fishes.
to test this, we could put a few of these fish in an isolated tank and see what kind of changes happen. If there are changes in the next generation, it will show that it could be the environment that changes the fishes. if they don't change in the next generations, it will show that it isn't the environment.
another test would be that we get a few of the same species and put them in isolated tanks with the same food and kind of water. if there are change in the next generations, it will show that the same species can produce different off spring and the foods and such could be a factor. if they all stay the same, the water, food, etc are not factors.
a final test that we could do is to see whether or not the small fishes get more food when they are around their own kind, or if they hang with the big koi. First let them both swim around for ---# of days/weeks/months and see how many are still alive or which are bigger at the end of the time-limit. if the ones that stayed with a big fish are bigger/have more fish alive than it will show that smaller fish benefit better by traveling around with big koi rather than with their own kind.
another observation i made was that the small fishes swim around in groups, but they also swim around bigger fishes. Before i thought that they only swam together to avoid confrontation with the big fishes.
to test this, we could put a few of these fish in an isolated tank and see what kind of changes happen. If there are changes in the next generation, it will show that it could be the environment that changes the fishes. if they don't change in the next generations, it will show that it isn't the environment.
another test would be that we get a few of the same species and put them in isolated tanks with the same food and kind of water. if there are change in the next generations, it will show that the same species can produce different off spring and the foods and such could be a factor. if they all stay the same, the water, food, etc are not factors.
a final test that we could do is to see whether or not the small fishes get more food when they are around their own kind, or if they hang with the big koi. First let them both swim around for ---# of days/weeks/months and see how many are still alive or which are bigger at the end of the time-limit. if the ones that stayed with a big fish are bigger/have more fish alive than it will show that smaller fish benefit better by traveling around with big koi rather than with their own kind.